The present invention relates to compacting vehicles, and more particularly to systems for controlling the steering and offset mechanisms of compacting vehicles.
Compacting vehicles or xe2x80x9ccompactorsxe2x80x9d used to compress a surface S, typically of soil or asphalt, are well known and generally include a frame and one or two compacting/driving drum members or xe2x80x9cdrumsxe2x80x9d. The frame of such vehicles is often formed of front and rear frame halves pivotally connected by an articulated joint. These compacting vehicles are generally steered using a hydraulic cylinder which actuates a steering linkage mechanism to pivot the rear frame half about the articulated joint, and thereby turn with respect to the front frame half. Further, such vehicles often have another hydraulic cylinder which operates an offset mechanism to displace the rear frame half laterally to one side or the other with respect to the front frame half.
Generally, the steering cylinder and the offset cylinder are each operated by a separate controller. As such, it is possible to operate the steering and offset mechanisms simultaneously, which creates a potential safety hazard and diminishes the operator""s ability to effectively control operation of the compacting vehicle.
It would therefore be desirable to have a compacting vehicle with a controller such that the steering and offset mechanisms cannot be simultaneously operated.
In a first aspect, the present invention is a control system for an industrial vehicle having and an articulated frame with left and right lateral sides and including a front frame half and a rear frame half movably connected with the front frame half. The system comprises a steering mechanism disposed between the front and rear frame halves and configured to pivot the rear frame half with respect to the front frame half. A first hydraulic actuator is operably connected with the steering mechanism. An offset mechanism is disposed between the front and rear frame halves and configured to displace the rear frame half with respect to the front frame half in a direction generally toward one of the lateral sides of the vehicle. A second hydraulic actuator is operably connected with the offset mechanism. Further, a hydraulic circuit includes a hydraulic fluid source and a selector valve device connected with the fluid source and with each of the first and second actuators. The selector valve is configured to selectively direct hydraulic fluid to the first actuator to operate the steering mechanism and alternatively to the second actuator to operate the offset mechanism.
In another aspect, the present invention is a compacting vehicle comprising an articulated frame having left and right lateral sides and including a front frame half and a rear frame half movably connected with the front frame half. At least one drum member is rotatably connected with one of the frame halves. A control system is mounted to the frame and includes a steering mechanism disposed between the front and rear frame halves and configured to pivot the rear frame half with respect to the front frame half. A first hydraulic actuator is operably connected with the steering mechanism. An offset mechanism is disposed between the front and rear frame halves and configured to displace the rear frame half with respect to the front frame half in a direction generally toward one of the lateral sides of the vehicle. A second hydraulic actuator is operably connected with the offset mechanism. Further, a hydraulic circuit includes a hydraulic fluid source and a selector valve device connected with the fluid source and with each of the first and second actuators. The selector valve is configured to selectively direct hydraulic fluid to the first actuator to operate the steering mechanism and alternatively to the second actuator to operate the offset mechanism.